It has been discovered that one of the unique features of scroll compressors is that it is ease to overheat while operating under abnormal conditions, such as operating under a compression ratio exceeding its specification, poor heat dissipation from its system condenser, blocked fan, clogged piping or the likes.
For preventing scroll compressors from being damaged by the aforesaid conditions, one known method is to design an apparatus in the scroll compressors that is specifically used for causing a low-pressure working fluid to flow toward a high-pressure zone, or/and causing a medium-pressure working fluid to a high-pressure zone when any of the aforesaid excessive temperature conditions is encountered, so as to protect scroll compressors from overheating. There are already many such apparatuses available today, such as those disclosed in U.S. Pat. Nos. 5,141,407, 6,267,565, and 7,338,265.
In detail, each of the U.S. Pat. Nos. 5,141,407 and 6,267,565 teaches an apparatus for protecting scroll compressors from high temperature problems, and the U.S. Pat. No. 7,338,265 teaches an apparatus for protecting scroll compressors from high pressure problems, according to that the apparatuses disclosed in U.S. Pat. Nos. 5,141,407 and 6,267,565 are not able to protect scroll compressors from being damaged by high pressure, and the apparatus disclosed in U.S. Pat. No. 7,338,265 is not able to protect scroll compressors from being damaged by high temperature. Thus, there are still a lot to be improved in those apparatuses disclosed in U.S. Pat. Nos. 5,141,407, 6,267,565, and 7,338,265.
Moreover, most current available scroll compressor is configured with a gliding block at the center thereof, which is designed to be driven to move by the pressure variation in the scroll compressor for allowing a high-pressure fluid to flow into a high-pressure chamber while preventing the same from leaking toward a low-pressure chamber as the scroll compressor is actuated. In addition, the aforesaid gliding block further comprises a backflow-proof element for reducing high-pressure backflow and thus preventing damage to the scroll pair of the scroll compressor.
However, as the acting force of the aforesaid gliding block design will concentrate to the center of the corresponding scroll pair, resulting that the contact area between the gliding block and the scroll pair is very small, the sealing between the gliding block and the scroll pair is not satisfactory.
In addition, the backflow-proof element formed in the gliding block is substantially a blind hole having a valve plate disposed therein. However, in reality, such blind hole design will cause the difficulty for machining a gliding block to increase.